[librsvg/librsvg-2.50] Hide implementation details of FilterValueList

[Federico Mena Quintero <federico src gnome org>]

commit f905a7facb8eb44709d8d81ecd98be1a64b137c9
Author: Sven Neumann <sven svenfoo org>
Date:   Wed Sep 9 09:39:20 2020 +0200

    Hide implementation details of FilterValueList
    
    We can hide the fact that FilterValueList uses a Vector by providing
    a method to create an Iterator over the contained values.

 rsvg_internals/src/drawing_ctx.rs | 1 -
 rsvg_internals/src/filter.rs      | 7 ++++++-
 2 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index a4f359b5..3687e098 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -599,7 +599,6 @@ impl DrawingCtx {
                         )?;
 
                         let img_surface = filters
-                            .0
                             .iter()
                             .try_fold(
                                 child_surface,
diff --git a/rsvg_internals/src/filter.rs b/rsvg_internals/src/filter.rs
index 6af6a9d2..abb34c8d 100644
--- a/rsvg_internals/src/filter.rs
+++ b/rsvg_internals/src/filter.rs
@@ -2,6 +2,7 @@
 
 use cssparser::Parser;
 use markup5ever::{expanded_name, local_name, namespace_url, ns};
+use std::slice::Iter;
 
 use crate::allowed_url::Fragment;
 use crate::bbox::BoundingBox;
@@ -196,7 +197,7 @@ pub enum FilterValue {
     URL(Fragment),
 }
 #[derive(Debug, Clone, PartialEq)]
-pub struct FilterValueList(pub Vec<FilterValue>);
+pub struct FilterValueList(Vec<FilterValue>);
 
 impl Default for FilterValueList {
     fn default() -> FilterValueList {
@@ -209,6 +210,10 @@ impl FilterValueList {
         self.0.is_empty()
     }
 
+    pub fn iter(&self) -> Iter<FilterValue> {
+        self.0.iter()
+    }
+
     /// Check that at least one filter URI exists and that all contained
     /// URIs reference existing <filter> elements.
     pub fn is_applicable(&self, node: &Node, acquired_nodes: &mut AcquiredNodes) -> bool {